Independent Submission R. Hay
Request for Comments: 5841 W. Turkal
Category: Informational Google Inc.
ISSN: 2070-1721 1 April 2010
TCP Option to Denote Packet Mood
Abstract
This document proposes a new TCP option to denote packet mood.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This is a contribution to the RFC Series, independently of any other
RFC stream. The RFC Editor has chosen to publish this document at
its discretion and makes no statement about its value for
implementation or deployment. Documents approved for publication by
the RFC Editor are not a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5841.
Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
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RFC 5841 TCP Option to Denote Packet Mood 1 April 20101. Introduction
In an attempt to anthropomorphize the bit streams on countless
physical layer networks throughout the world, we propose a TCP option
to express packet mood [DSM-IV].
Packets cannot feel. They are created for the purpose of moving data
from one system to another. However, it is clear that in specific
situations some measure of emotion can be inferred or added. For
instance, a packet that is retransmitted to resend data for a packet
for which no ACK was received could be described as an 'angry'
packet, or a 'frustrated' packet (if it is not the first
retransmission for instance). So how can these kinds of feelings be
conveyed in the packets themselves. This can be addressed by adding
TCP Options [RFC793] to the TCP header, using ASCII characters that
encode commonly used "emoticons" to convey packet mood.
1.1. Terminology
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL, when they appear in this
document, are to be interpreted as described in [RFC2119].
2. Syntax
A TCP Option has a 1-byte kind field, followed by a 1-byte length
field [RFC793]. It is proposed that option 25 (released 2000-12-18)
be used to define packet mood. This option would have a length value
of 4 or 5 bytes. All the simple emotions described as expressible
via this mechanism can be displayed with two or three 7-bit, ASCII-
encoded characters. Multiple mood options may appear in a TCP
header, so as to express more complex moods than those defined here
(for instance if a packet were happy and surprised).
TCP Header Format
Kind Length Meaning
---- -------- -------
25 Variable Packet Mood
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RFC 5841 TCP Option to Denote Packet Mood 1 April 2010
Proposed ASCII character encoding
Binary Dec Hex Character
======== === === =========
010 0101 37 25 %
010 1000 40 28 (
010 1001 41 29 )
011 1010 58 3A :
011 1011 59 3B ;
011 1110 62 3E >
100 0000 64 40 @
100 0100 68 44 D
100 1111 79 4F O
101 0000 80 50 P
110 1111 111 6F o
111 1100 124 7C |
For the purposes of this RFC, 7-bit ASCII encoding is sufficient for
representing emoticons. The ASCII characters will be sent in 8-bit
bytes with the leading bit always set to 0.
4. Use Cases
There are two ways to denote packet mood. One is to infer the mood
based on an event in the TCP session. The other is to derive mood
from a higher-order action at a higher layer (subject matter of
payload for instance).
For packets where the 'mood' is inferred from activity within the TCP
session, the 'mood' MUST be set by the host that is watching for the
trigger event. If a client sends a frame and receives no ACK, then
the retransmitted frame MAY contain the TCP OPTION header with a mood
set.
Any packet that exhibits behavior that allows for mood to be inferred
SHOULD add the TCP OPTION to the packets with the implied mood.
Applications can take advantage of the defined moods by expressing
them in the packets. This can be done in the SYN packet sent from
the client. All packets in the session can be then tagged with the
mood set in the SYN packet, but this would have a per-packet
performance cost (see Section 5, "Performance Considerations").
Each application MUST define the preconditions for marking packets as
happy, sad, bored, confused, angry, apathetic, and so on. This is a
framework for defining how such moods can be expressed, but it is up
to the developers to determine when to apply these encoded labels.
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RFC 5841 TCP Option to Denote Packet Mood 1 April 20104.1. Happy Packets
Healthy packets are happy packets you could say. If the ACK packets
return within <10 ms end-to-end from a sender's stack to a receiver's
stack and back again, this would reflect high-speed bidirectional
capability, and if no retransmits are required and all ACKs are
received, all subsequent packets in that session SHOULD be marked as
'happy'.
No loss, low-latency packets also makes for happy users. So the
packet would be reflecting the end-user experience.
4.2. Sad Packets
If retransmission rates achieve greater than 20% of all packets sent
in a session, it is fair to say the session can be in mourning for
all of the good packets lost in the senseless wasteland of the wild
Internet.
This should not be confused with retransmitted packets marked as
'angry' since this tag would apply to all frames in the session
numbed by the staggering loss of packet life.
4.3. Amused Packets
Any packet that is carrying a text joke SHOULD be marked as 'amused'.
Example:
1: Knock Knock
2: Who's there?
1: Impatient chicken
2: Impatient chi...
1: BAWK!!!!
If such a joke is in the packet payload then, honestly, how can you
not be amused by one of the only knock-knock jokes that survives the
3rd grade?
4.4. Confused Packets
When is a packet confused? There are network elements that perform
per-packet load balancing, and if there are asymmetries in the
latencies between end-to-end paths, out-of-order packet delivery can
occur.
When a receiver host gets out-of-order packets, it SHOULD mark TCP
ACK packets sent back to the sender as confused.
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RFC 5841 TCP Option to Denote Packet Mood 1 April 2010
The same can be said for packets that are sent to incorrect VLAN
segments or are misdirected. The receivers might be aware that the
packet is confused, but there is no way to know at ingress if that
will be the fate of the frame.
That being said, application developers SHOULD mark packets as
confused if the payload contains complex philosophical questions that
make one ponder the meaning of life and one's place in the universe.
4.5. Bored Packets
Packets carrying accounting data with debits, credits, and so on MUST
be marked as 'bored'.
It could be said that many people consider RFCs boring. Packets
containing RFC text MAY be marked as 'bored'.
Packets with phone book listings MUST be marked 'bored'.
Packets containing legal disclaimers and anything in Latin SHOULD be
marked 'bored'.
4.6. Surprised Packets
Who doesn't love when the out-of-order packets in your session
surprise you while waiting in a congested queue for 20 ms?
Packets do not have birthdays, so packets can be marked as surprised
when they encounter unexpected error conditions.
So when ICMP destination unreachable messages are received (perhaps
due to a routing loop or congestion discards), all subsequent packets
in that session SHOULD be marked as surprised.
4.7. Silly Packets
Not all packets are sent as part of a session. Random keepalives
during a TCP session MAY be set up as a repartee between systems
connected as client and server. Such random and even playful
interchanges SHOULD be marked as silly.
4.8. Frustrated Packets
Packets that are retransmitted more than once SHOULD be marked as
frustrated.
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RFC 5841 TCP Option to Denote Packet Mood 1 April 20104.9. Angry Packets
Packets that are retransmitted SHOULD be marked as angry.
4.10. Apathetic Packets
When sending a RST packet to a connected system, the packet should be
marked as apathetic so that the receiver knows that your system does
not care what happens after that.
4.11. Sneaky Packets
When a packet is used in a particularly clever way, it SHOULD be
marked as sneaky. What is "clever" is rather subjective, so it would
be prudent to get a few opinions about a particular use to make sure
that it is clever.
4.12. Evil Packets
It is hard for a TCP packet to discern higher moral quandaries like
the meaning of life or what exactly defines 'evil' and from whose
perspective such a characterization is being made. However,
developers of TCP-based applications MAY choose to see some
activities as evil when viewed through their particular lens of the
world. At that point, they SHOULD mark packets as evil.
Some organizations are prohibited from using this mood by mission
statement. This would also prohibit using the security flag in the
IP header described in [RFC3514] for the same reasons.
5. Performance Considerations
Adding extensions to the TCP header has a cost. Using TCP extensions
with the ASCII-encoded mood of the packet would detract from the
available MSS usable for data payload. If the TCP header is more
than 20 bytes, then the extra bytes would be unavailable for use in
the payload of the frame.
This added per-packet overhead should be considered when using packet
mood extensions.
6. Security Considerations
The TCP checksum, as a 16-bit value, could be mistaken if ASCII
characters with the same number of zeros and ones were substituted
out. A happy ":)" could be replaced with a frown by a malicious
attacker, by using a winking eye ";(". This could misrepresent the
intended mood of the sender to the receiver.
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RFC 5841 TCP Option to Denote Packet Mood 1 April 20107. Related Work
This document does not seek to build a sentient network stack.
However, this framework could be used to express the emotions of a
sentient stack. If that were to happen, a new technical job class of
network psychologists could be created. Who doesn't like new jobs?
:)
8. IANA Considerations
If this work is standardized, IANA is requested to officially assign
value 25 as described in Section 3. Additional moods and emoticon
representations would require IESG approval or standards action
[RFC5226].
9. Informative References
[DSM-IV] "Diagnostic and Statistical Manual of Mental Disorders
(DSM)", http://www.psychiatryonline.com/resourceTOC.aspx?resourceID=1.
[RFC793] Postel, J., "Transmission Control Protocol", STD 7, RFC793, September 1981.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, May
2008.
[RFC3514] Bellovin, S., "The Security Flag in the IPv4 Header", RFC3514, April 1 2003.
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